One of the interesting properties of cells that are in exponential growth is that the time to increase the cell number by a factor of 2 is always the same.

细胞有一个有趣的性质,那就是在指数增长阶段,细胞增长的速度,永远是以二为底数来增长的

耶鲁公开课 - 生物医学工程探索课程节选

One answer, and it's the one that is most widely believed among Greek scholars, is that the growth of population that we have mentioned in connection with the rise of the polis is still working once the polis comes into form.

原因之一是,这个原因是被广大古希腊学者们所接受的,那就是,人口的增长与城邦的数量,在城邦兴起的阶段还是基本一致的

耶鲁公开课 - 古希腊历史简介课程节选